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THERMODYNAMIC COEFFICIENTS OF REAL GASES DERIVED FROM THE EXPERIMENTAL SPEED OF SOUND

COEFICIENTES TERMODINÁMICOS DE GASES REALES DERIVADOS DE LA VELOCIDAD EXPERIMENTAL DEL SONIDO

Author(s): Neimarlija N (Neimarlija, Nagib)1, Bijedic M (Bijedic, Muhamed)2 Source: TRANSACTIONS OF FAMENA    Volume: 33    Issue: 2    Pages: 91-99    Published: 2009   TimesCited: 0     References: 7     Citation Map    
Abstract: A new method for deriving thermodynamic coefficients (isentropic coefficient, adiabatic compressibility, volume expansivity and isothermal compressibility) from the speed Of Sound has been worked Out. The method is based on the numerical integration of differential equations connecting the speed of Sound with other thermodynamicproperties. It requires data of initial values of density and heat capacity at a single temperature in the pressure range of interest. The method was tested by deriving the isentropic coefficient and the adiabatic compressibility of gaseous argon in the temperatures between 250 and 450 K, and in the pressure range from 0.2 to 12 MPa. The absolute average deviation between the calculated and referencevalues Of the isentropic coefficient and the adiabatic compressibility is 0.007% and 0.008%, respectively. The method was also tested by deriving the volume expansivity and the isothermal compressibility coefficients Of gaseous methane in the temperatures between 275 and 375 K, and in the pressure range from 0.4 to 10 MPa. The absolute average deviation between the calculated and reference values ofthe volume expansivity and the isothermal compressibility coefficients is 0.052% and 0.011%, respectively.

Resumen: Un nuevo método para obtener los coeficientes de termodinámica (coeficiente de compresibilidad isentrópico, adiabático, expansividad del volumen y la compresibilidad isotérmica de la velocidad del sonido) se ha elaborado. El método se basa en la integración numérica de ecuacionesdiferenciales de conectar la velocidad del sonido con otras propiedades termodinámicas. Se requiere que los datos de los valores iniciales de densidad y capacidad calorífica a una sola temperatura en el rango de presión de interés. El método fue probado mediante la derivación del coeficiente isentrópico y la compresibilidad adiabática de argón gaseoso en las temperaturas entre 250 y 450 K, y en elrango de presión de 0,2 a 12 MPa. La desviación absoluta media entre los valores calculados y referencia del coeficiente isentrópico y la compresibilidad adiabática es de 0,007% y 0,008%, respectivamente. El método ha sido probado también por derivar la expansividad del volumen y los coeficientes de compresibilidad isotérmica de metano gaseoso en temperaturas de entre 275 y K 375, y en el rango depresión de 0,4 a 10 MPa. La desviación absoluta media entre los valores calculados, la referencia de la expansividad del volumen y los coeficientes de compresibilidad isotérmica es 0,052% y 0,011%, respectivamente.

Real Gases in the Heterogeneous Reactions of Solid Fuel and the Effect of the Compressibility of Condensed Liquid on Gas State Parameters

Los gases reales en las reaccionesheterogéneas de combustible sólido y el efecto de la compresibilidad del líquido condensado en parámetros Gas del Estado

Author(s): Zakharov AG (Zakharov, A. G.) Source: SOLID FUEL CHEMISTRY    Volume: 42    Issue: 5    Pages: 289-297    Published: OCT 2008   Times Cited: 0     References: 6     Citation Map     
Abstract: Changes in the number of molecules in the gaseous phase of a closed volumeunder compression with the occurrence of a condensation process were studied. A corresponding relationship, which predicted the occurrence of two regimes in the development of a compression process and the possibility of a transition from one regime to the other at a critical point, was obtained. The effect of molecular size on the parameters responsible for this transition was demonstrated, and...